1. Field of the Invention
The present invention relates to a portable disk drive assembly which has an outer layer of elastomer material which both seals the assembly and absorbs external shock or vibrational loads that are applied to the disk drive.
2. Description of Related Art
Most computer systems include a massive memory storage device such as a hard disk drive. Hard disk drive units contain a magnetic disk that is capable of storing a large amount of binary information. The magnetic disk is typically coupled to a hub which is rotated by an electric motor. The drive unit also has a head that magnetizes and senses the magnetic field of the disk. The head is typically located at the end of an actuator arm which can move relative to the magnetic disk. The actuator arm, motor and other components of a typical disk drive unit are relatively small and fragile, and are therefore susceptible to damage when subjected to excessive external shock loads or vibration. For this reason, hard disk drives are typically rigidly mounted to the housing of the computer system by screws or other fastening means.
Hard disk drives contain programs and other information that are vital to the user. It is sometimes desirable to transfer such information to a different computer system. Transferring programs from a hard disk typically requires loading the information onto a floppy disk, or sending such information over a phone line. Such methods can be time consuming, particularly if the program is long or there is a large amount of data. There have been developed portable hard disk drives which can be plugged into a slot in the computer. To reduce the amount of possible component damage to the drive unit, the housing and assembly are typically constructed to be quite rugged. These rugged assemblies are typically heavy and bulky, and generally impractical to carry and store.
The Personal Computer Memory Card International Association (PCMCIA) has recently promulgated specifications for portable memory cards which can be plugged into slots within a computer. The PCMCIA standard includes a type I format, a type II format and a type III format, each format being distinguished by a different card thickness. Memory can be added to a computer by merely plugging in an additional card. Similarly, a modem or facsimile (FAX) card can be added to a system with a push of the hand. The standardized format of the card allows a user to plug the memory card of one computer into another computer regardless of the type or make of either system.
The standardized cards are approximately the size of a credit card and include a connector which mates with a connector in the computer. The small size of the card provides an electronic assembly that is easy to carry and store. It would be very desirable to have a hard disk drive unit which conforms with the PCMCIA format, so that the disk drive can be readily carried and plugged into an existing slot of a computer. Such a hard disk card must be rugged enough to withstand the large shock loads that may be applied to the drive unit, such as by dropping the card onto a hard surface. It would therefore be desirable to have a hard disk drive unit which would be small enough to meet the PCMCIA format and rugged enough to be used as a portable disk drive unit.